HarmonyOS ArkTS 通用事件（二十三）

点击事件

组件被点击时触发的事件。

事件

ClickEvent对象说明

从API version 9开始，该接口支持在ArkTS卡片中使用。

EventTarget8+对象说明

示例

// xxx.ets
@Entry
@Component
struct ClickExample {
  @State text: string = ''

  build() {
    Column() {
      Row({ space: 20 }) {
        Button('Click').width(100).height(40)
          .onClick((event: ClickEvent) => {
            this.text = 'Click Point:' + '\n  screenX:' + event.screenX + '\n  screenY:' + event.screenY
            + '\n  x:' + event.x + '\n  y:' + event.y + '\ntarget:' + '\n  component globalPos:('
            + event.target.area.globalPosition.x + ',' + event.target.area.globalPosition.y + ')\n  width:'
            + event.target.area.width + '\n  height:' + event.target.area.height + '\ntimestamp' + event.timestamp;
          })
        Button('Click').width(200).height(50)
          .onClick((event: ClickEvent) => {
            this.text = 'Click Point:' + '\n  screenX:' + event.screenX + '\n  screenY:' + event.screenY
            + '\n  x:' + event.x + '\n  y:' + event.y + '\ntarget:' + '\n  component globalPos:('
            + event.target.area.globalPosition.x + ',' + event.target.area.globalPosition.y + ')\n  width:'
            + event.target.area.width + '\n  height:' + event.target.area.height + '\ntimestamp' + event.timestamp;
          })
      }.margin(20)

      Text(this.text).margin(15)
    }.width('100%')
  }
}

触摸事件

当手指在组件上按下、滑动、抬起时触发。

事件

TouchEvent对象说明

TouchObject对象说明

示例

// xxx.ets
@Entry
@Component
struct TouchExample {
  @State text: string = ''
  @State eventType: string = ''

  build() {
    Column() {
      Button('Touch').height(40).width(100)
        .onTouch((event: TouchEvent) => {
          if (event.type === TouchType.Down) {
            this.eventType = 'Down'
          }
          if (event.type === TouchType.Up) {
            this.eventType = 'Up'
          }
          if (event.type === TouchType.Move) {
            this.eventType = 'Move'
          }
          this.text = 'TouchType:' + this.eventType + '\nDistance between touch point and touch element:\nx: '
          + event.touches[0].x + '\n' + 'y: ' + event.touches[0].y + '\nComponent globalPos:('
          + event.target.area.globalPosition.x + ',' + event.target.area.globalPosition.y + ')\nwidth:'
          + event.target.area.width + '\nheight:' + event.target.area.height
        })
      Button('Touch').height(50).width(200).margin(20)
        .onTouch((event: TouchEvent) => {
          if (event.type === TouchType.Down) {
            this.eventType = 'Down'
          }
          if (event.type === TouchType.Up) {
            this.eventType = 'Up'
          }
          if (event.type === TouchType.Move) {
            this.eventType = 'Move'
          }
          this.text = 'TouchType:' + this.eventType + '\nDistance between touch point and touch element:\nx: '
          + event.touches[0].x + '\n' + 'y: ' + event.touches[0].y + '\nComponent globalPos:('
          + event.target.area.globalPosition.x + ',' + event.target.area.globalPosition.y + ')\nwidth:'
          + event.target.area.width + '\nheight:' + event.target.area.height
        })
      Text(this.text)
    }.width('100%').padding(30)
  }
}

挂载卸载事件

挂载卸载事件指组件从组件树上挂载、卸载时触发的事件。

事件

示例

// xxx.ets
import promptAction from '@ohos.promptAction'

@Entry
@Component
struct AppearExample {
  @State isShow: boolean = true
  @State changeAppear: string = '点我卸载挂载组件'
  private myText: string = 'Text for onAppear'

  build() {
    Column() {
      Button(this.changeAppear)
        .onClick(() => {
          this.isShow = !this.isShow
        }).margin(15)
      if (this.isShow) {
        Text(this.myText).fontSize(26).fontWeight(FontWeight.Bold)
          .onAppear(() => {
            promptAction.showToast({
              message: 'The text is shown',
              duration: 2000
            })
          })
          .onDisAppear(() => {
            promptAction.showToast({
              message: 'The text is hidden',
              duration: 2000
            })
          })
      }
    }.padding(30).width('100%')
  }
}